and (Economy of the Araneidca. 229 



Another ninle Tvgenarid civilis, after undergoing the same treat- 

 ment exactly as that in the preceding cxperini» nt, was introduced, 

 on the f)tli ot" May 1812, to a female of its own r.pecies, which had 

 been in solitary continement from the 25th of January 184-0, and 

 had cast its skin three times during its captivity. This fenmle re- 

 ceived the embraces of the male as soon as he was admitted into 

 the phial to her, and laid a set of eggs on the 27th of the same month, 

 all of which were productive, the young lieginning to be disengaged 

 from them on the 27th of the ensuing month. 



In stating a further repetition of this experiment with spiders of 

 the same species, it is only necessary to premise that the female had 

 cast her skin three times in captivity, and that the male had but the 

 right palpus, the other having been removed by amputation. They 

 were placed together on the 16th of May IS 1-2, paired the same day, 

 and were separated as soon as their union was accomplished. On 

 the 19th of June the female de[)osited a set of eggs in a cocoon, 

 which began to be hatched on the 24-th of the following July, and 

 all produced young. Without further sexual intercourse, in 184-3 

 she enveloped a set of eggs in a cocoon on the 7th of April, the 5th 

 of May, the 1st of .June, the 18th of June, and the 3rd of July, re- 

 spectively, from all which young were disengaged. 



Promptness in accommodating itself to the restraint of confine- 

 ment, together with the certainty of being able to procure specimens 

 whenever they might be required, led to the selection of Tege7iaria 

 civilis as a suitable subject for the foregoing experiments, from which, 

 conjointly with the preceding observations, the following inferences 

 may be deduced : — 



1st. That female spiders are incapable of producing prolific eggs 

 without sexual intercourse. 



2nd. That females which have not been impregnated occasionally 

 produce sterile eggs. 



3rd. That the female of Tegenaria civilis, when impregnated, is 

 capable of producing several sets of prolific eggs in succes>ion with- 

 out renewing its intercourse with the male*, two years or more oc- 

 casionally elapsing before all are deposited, and a period of ten 

 months nearly intervening sometimes between the deposition of two 

 consecutive sets. 



4th. That spiders of various species copulate without the abdo- 

 men of the male being brought into contact with that of the female. 



5th. That male spiders, in which the part, stated by Treviranus 

 to be the seat of the sexual organs, is entirely covered with strong, 

 well-gummed writing paper closely applied, nevertheless possess the 

 power of exercising the function of generation unimpaired. 



6th. Lastly, that males so circumstanced invariably consummate 

 the act by applying the palpal organs to the vulva of females, plainly 

 demonstrating thereby the interesting truth, that those organs, 

 however anomalous their situation may be, are the only efficient 



* Tef^enaria domestlca {^Aranea domestica, Linn.), A;jelena labyrinthica, and 

 Epeiia cucurbitiiin are endowed with similar powers of produftion. Fide the Re- 

 port of the Third Meeting of the British Association, p. l-lj. 



